2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
8 * This file is released under the GPLv2.
11 #define pr_fmt(fmt) "PM: " fmt
13 #include <linux/string.h>
14 #include <linux/delay.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/console.h>
18 #include <linux/cpu.h>
19 #include <linux/cpuidle.h>
20 #include <linux/gfp.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
25 #include <linux/slab.h>
26 #include <linux/export.h>
27 #include <linux/suspend.h>
28 #include <linux/syscore_ops.h>
29 #include <linux/swait.h>
30 #include <linux/ftrace.h>
31 #include <trace/events/power.h>
32 #include <linux/compiler.h>
33 #include <linux/moduleparam.h>
37 const char * const pm_labels[] = {
38 [PM_SUSPEND_TO_IDLE] = "freeze",
39 [PM_SUSPEND_STANDBY] = "standby",
40 [PM_SUSPEND_MEM] = "mem",
42 const char *pm_states[PM_SUSPEND_MAX];
43 static const char * const mem_sleep_labels[] = {
44 [PM_SUSPEND_TO_IDLE] = "s2idle",
45 [PM_SUSPEND_STANDBY] = "shallow",
46 [PM_SUSPEND_MEM] = "deep",
48 const char *mem_sleep_states[PM_SUSPEND_MAX];
50 suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
51 suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
52 suspend_state_t pm_suspend_target_state;
53 EXPORT_SYMBOL_GPL(pm_suspend_target_state);
55 unsigned int pm_suspend_global_flags;
56 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
58 static const struct platform_suspend_ops *suspend_ops;
59 static const struct platform_s2idle_ops *s2idle_ops;
60 static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
62 enum s2idle_states __read_mostly s2idle_state;
63 static DEFINE_RAW_SPINLOCK(s2idle_lock);
65 bool pm_suspend_via_s2idle(void)
67 return mem_sleep_current == PM_SUSPEND_TO_IDLE;
69 EXPORT_SYMBOL_GPL(pm_suspend_via_s2idle);
71 void s2idle_set_ops(const struct platform_s2idle_ops *ops)
75 unlock_system_sleep();
78 static void s2idle_begin(void)
80 s2idle_state = S2IDLE_STATE_NONE;
83 static void s2idle_enter(void)
85 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
87 raw_spin_lock_irq(&s2idle_lock);
88 if (pm_wakeup_pending())
91 s2idle_state = S2IDLE_STATE_ENTER;
92 raw_spin_unlock_irq(&s2idle_lock);
97 /* Push all the CPUs into the idle loop. */
98 wake_up_all_idle_cpus();
99 /* Make the current CPU wait so it can enter the idle loop too. */
100 swait_event_exclusive(s2idle_wait_head,
101 s2idle_state == S2IDLE_STATE_WAKE);
106 raw_spin_lock_irq(&s2idle_lock);
109 s2idle_state = S2IDLE_STATE_NONE;
110 raw_spin_unlock_irq(&s2idle_lock);
112 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
115 static void s2idle_loop(void)
117 pm_pr_dbg("suspend-to-idle\n");
125 * Suspend-to-idle equals
126 * frozen processes + suspended devices + idle processors.
127 * Thus s2idle_enter() should be called right after
128 * all devices have been suspended.
130 * Wakeups during the noirq suspend of devices may be spurious,
131 * so prevent them from terminating the loop right away.
133 error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
136 else if (error == -EBUSY && pm_wakeup_pending())
139 if (!error && s2idle_ops && s2idle_ops->wake)
142 dpm_noirq_resume_devices(PMSG_RESUME);
149 if (s2idle_ops && s2idle_ops->sync)
152 if (pm_wakeup_pending())
155 pm_wakeup_clear(false);
158 pm_pr_dbg("resume from suspend-to-idle\n");
161 void s2idle_wake(void)
165 raw_spin_lock_irqsave(&s2idle_lock, flags);
166 if (s2idle_state > S2IDLE_STATE_NONE) {
167 s2idle_state = S2IDLE_STATE_WAKE;
168 swake_up_one(&s2idle_wait_head);
170 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
172 EXPORT_SYMBOL_GPL(s2idle_wake);
174 static bool valid_state(suspend_state_t state)
177 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
178 * support and need to be valid to the low level
179 * implementation, no valid callback implies that none are valid.
181 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
184 void __init pm_states_init(void)
186 /* "mem" and "freeze" are always present in /sys/power/state. */
187 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
188 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
190 * Suspend-to-idle should be supported even without any suspend_ops,
191 * initialize mem_sleep_states[] accordingly here.
193 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
196 static int __init mem_sleep_default_setup(char *str)
198 suspend_state_t state;
200 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
201 if (mem_sleep_labels[state] &&
202 !strcmp(str, mem_sleep_labels[state])) {
203 mem_sleep_default = state;
209 __setup("mem_sleep_default=", mem_sleep_default_setup);
212 * suspend_set_ops - Set the global suspend method table.
213 * @ops: Suspend operations to use.
215 void suspend_set_ops(const struct platform_suspend_ops *ops)
221 if (valid_state(PM_SUSPEND_STANDBY)) {
222 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
223 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
224 if (mem_sleep_default == PM_SUSPEND_STANDBY)
225 mem_sleep_current = PM_SUSPEND_STANDBY;
227 if (valid_state(PM_SUSPEND_MEM)) {
228 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
229 if (mem_sleep_default >= PM_SUSPEND_MEM)
230 mem_sleep_current = PM_SUSPEND_MEM;
233 unlock_system_sleep();
235 EXPORT_SYMBOL_GPL(suspend_set_ops);
238 * suspend_valid_only_mem - Generic memory-only valid callback.
240 * Platform drivers that implement mem suspend only and only need to check for
241 * that in their .valid() callback can use this instead of rolling their own
244 int suspend_valid_only_mem(suspend_state_t state)
246 return state == PM_SUSPEND_MEM;
248 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
250 static bool sleep_state_supported(suspend_state_t state)
252 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
255 static int platform_suspend_prepare(suspend_state_t state)
257 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
258 suspend_ops->prepare() : 0;
261 static int platform_suspend_prepare_late(suspend_state_t state)
263 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
264 s2idle_ops->prepare() : 0;
267 static int platform_suspend_prepare_noirq(suspend_state_t state)
269 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
270 suspend_ops->prepare_late() : 0;
273 static void platform_resume_noirq(suspend_state_t state)
275 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
279 static void platform_resume_early(suspend_state_t state)
281 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
282 s2idle_ops->restore();
285 static void platform_resume_finish(suspend_state_t state)
287 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
288 suspend_ops->finish();
291 static int platform_suspend_begin(suspend_state_t state)
293 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
294 return s2idle_ops->begin();
295 else if (suspend_ops && suspend_ops->begin)
296 return suspend_ops->begin(state);
301 static void platform_resume_end(suspend_state_t state)
303 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
305 else if (suspend_ops && suspend_ops->end)
309 static void platform_recover(suspend_state_t state)
311 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
312 suspend_ops->recover();
315 static bool platform_suspend_again(suspend_state_t state)
317 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
318 suspend_ops->suspend_again() : false;
321 #ifdef CONFIG_PM_DEBUG
322 static unsigned int pm_test_delay = 5;
323 module_param(pm_test_delay, uint, 0644);
324 MODULE_PARM_DESC(pm_test_delay,
325 "Number of seconds to wait before resuming from suspend test");
328 static int suspend_test(int level)
330 #ifdef CONFIG_PM_DEBUG
331 if (pm_test_level == level) {
332 pr_info("suspend debug: Waiting for %d second(s).\n",
334 mdelay(pm_test_delay * 1000);
337 #endif /* !CONFIG_PM_DEBUG */
342 * suspend_prepare - Prepare for entering system sleep state.
344 * Common code run for every system sleep state that can be entered (except for
345 * hibernation). Run suspend notifiers, allocate the "suspend" console and
348 static int suspend_prepare(suspend_state_t state)
350 int error, nr_calls = 0;
352 if (!sleep_state_supported(state))
355 pm_prepare_console();
357 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
363 trace_suspend_resume(TPS("freeze_processes"), 0, true);
364 error = suspend_freeze_processes();
365 trace_suspend_resume(TPS("freeze_processes"), 0, false);
369 suspend_stats.failed_freeze++;
370 dpm_save_failed_step(SUSPEND_FREEZE);
372 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
373 pm_restore_console();
377 /* default implementation */
378 void __weak arch_suspend_disable_irqs(void)
383 /* default implementation */
384 void __weak arch_suspend_enable_irqs(void)
390 * suspend_enter - Make the system enter the given sleep state.
391 * @state: System sleep state to enter.
392 * @wakeup: Returns information that the sleep state should not be re-entered.
394 * This function should be called after devices have been suspended.
396 static int suspend_enter(suspend_state_t state, bool *wakeup)
400 error = platform_suspend_prepare(state);
402 goto Platform_finish;
404 error = dpm_suspend_late(PMSG_SUSPEND);
406 pr_err("late suspend of devices failed\n");
407 goto Platform_finish;
409 error = platform_suspend_prepare_late(state);
411 goto Devices_early_resume;
413 if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
415 goto Platform_early_resume;
418 error = dpm_suspend_noirq(PMSG_SUSPEND);
420 pr_err("noirq suspend of devices failed\n");
421 goto Platform_early_resume;
423 error = platform_suspend_prepare_noirq(state);
427 if (suspend_test(TEST_PLATFORM))
430 error = suspend_disable_secondary_cpus();
431 if (error || suspend_test(TEST_CPUS))
434 arch_suspend_disable_irqs();
435 BUG_ON(!irqs_disabled());
437 system_state = SYSTEM_SUSPEND;
439 error = syscore_suspend();
441 *wakeup = pm_wakeup_pending();
442 if (!(suspend_test(TEST_CORE) || *wakeup)) {
443 trace_suspend_resume(TPS("machine_suspend"),
445 error = suspend_ops->enter(state);
446 trace_suspend_resume(TPS("machine_suspend"),
448 } else if (*wakeup) {
454 system_state = SYSTEM_RUNNING;
456 arch_suspend_enable_irqs();
457 BUG_ON(irqs_disabled());
460 suspend_enable_secondary_cpus();
463 platform_resume_noirq(state);
464 dpm_resume_noirq(PMSG_RESUME);
466 Platform_early_resume:
467 platform_resume_early(state);
469 Devices_early_resume:
470 dpm_resume_early(PMSG_RESUME);
473 platform_resume_finish(state);
478 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
479 * @state: System sleep state to enter.
481 int suspend_devices_and_enter(suspend_state_t state)
486 if (!sleep_state_supported(state))
489 pm_suspend_target_state = state;
491 error = platform_suspend_begin(state);
496 suspend_test_start();
497 error = dpm_suspend_start(PMSG_SUSPEND);
499 pr_err("Some devices failed to suspend, or early wake event detected\n");
500 goto Recover_platform;
502 suspend_test_finish("suspend devices");
503 if (suspend_test(TEST_DEVICES))
504 goto Recover_platform;
507 error = suspend_enter(state, &wakeup);
508 } while (!error && !wakeup && platform_suspend_again(state));
511 suspend_test_start();
512 dpm_resume_end(PMSG_RESUME);
513 suspend_test_finish("resume devices");
514 trace_suspend_resume(TPS("resume_console"), state, true);
516 trace_suspend_resume(TPS("resume_console"), state, false);
519 platform_resume_end(state);
520 pm_suspend_target_state = PM_SUSPEND_ON;
524 platform_recover(state);
529 * suspend_finish - Clean up before finishing the suspend sequence.
531 * Call platform code to clean up, restart processes, and free the console that
532 * we've allocated. This routine is not called for hibernation.
534 static void suspend_finish(void)
536 suspend_thaw_processes();
537 pm_notifier_call_chain(PM_POST_SUSPEND);
538 pm_restore_console();
542 * enter_state - Do common work needed to enter system sleep state.
543 * @state: System sleep state to enter.
545 * Make sure that no one else is trying to put the system into a sleep state.
546 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
547 * system enter the given sleep state and clean up after wakeup.
549 static int enter_state(suspend_state_t state)
553 trace_suspend_resume(TPS("suspend_enter"), state, true);
554 if (state == PM_SUSPEND_TO_IDLE) {
555 #ifdef CONFIG_PM_DEBUG
556 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
557 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
561 } else if (!valid_state(state)) {
564 if (!mutex_trylock(&system_transition_mutex))
567 if (state == PM_SUSPEND_TO_IDLE)
570 if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) {
571 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
573 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
576 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
577 pm_suspend_clear_flags();
578 error = suspend_prepare(state);
582 if (suspend_test(TEST_FREEZER))
585 trace_suspend_resume(TPS("suspend_enter"), state, false);
586 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
587 pm_restrict_gfp_mask();
588 error = suspend_devices_and_enter(state);
589 pm_restore_gfp_mask();
592 events_check_enabled = false;
593 pm_pr_dbg("Finishing wakeup.\n");
596 mutex_unlock(&system_transition_mutex);
601 * pm_suspend - Externally visible function for suspending the system.
602 * @state: System sleep state to enter.
604 * Check if the value of @state represents one of the supported states,
605 * execute enter_state() and update system suspend statistics.
607 int pm_suspend(suspend_state_t state)
611 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
614 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
615 error = enter_state(state);
617 suspend_stats.fail++;
618 dpm_save_failed_errno(error);
620 suspend_stats.success++;
622 pr_info("suspend exit\n");
625 EXPORT_SYMBOL(pm_suspend);